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Posted to issues@beam.apache.org by "Dénes Bartha (Jira)" <ji...@apache.org> on 2021/02/25 03:24:00 UTC
[jira] [Created] (BEAM-11862) Write To Kafka does not work
Dénes Bartha created BEAM-11862:
-----------------------------------
Summary: Write To Kafka does not work
Key: BEAM-11862
URL: https://issues.apache.org/jira/browse/BEAM-11862
Project: Beam
Issue Type: Bug
Components: io-py-kafka
Affects Versions: 2.28.0
Reporter: Dénes Bartha
I am trying to send data to a Kafka topic in Python using {{WriteToKafka}} via Apache Beam using Dataflow as a runner.
By running the following script:
{code:java}
with beam.Pipeline(options=beam_options) as p:
(p
| beam.Impulse()
| beam.Map(lambda input: (1, input))
| WriteToKafka(
producer_config={
'bootstrap.servers': 'ip:9092,',
},
topic='testclient',
key_serializer='org.apache.kafka.common.serialization.LongSerializer',
value_serializer='org.apache.kafka.common.serialization.ByteArraySerializer',
)
)
{code}
I am getting this error:
Traceback (most recent call last):
File "/home/denes/data-science/try_write_to_kafka.py", line 75, in <module>
run_pipeline(beam_options)
File "/home/denes/data-science/try_write_to_kafka.py", line 38, in run_pipeline
(p
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/pipeline.py", line 582, in __exit__
self.result = self.run()
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/pipeline.py", line 529, in run
return Pipeline.from_runner_api(
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/pipeline.py", line 904, in from_runner_api
p.transforms_stack = [context.transforms.get_by_id(root_transform_id)]
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/runners/pipeline_context.py", line 115, in get_by_id
self._id_to_obj[id] = self._obj_type.from_runner_api(
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/pipeline.py", line 1259, in from_runner_api
part = context.transforms.get_by_id(transform_id)
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/runners/pipeline_context.py", line 115, in get_by_id
self._id_to_obj[id] = self._obj_type.from_runner_api(
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/pipeline.py", line 1259, in from_runner_api
part = context.transforms.get_by_id(transform_id)
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/runners/pipeline_context.py", line 115, in get_by_id
self._id_to_obj[id] = self._obj_type.from_runner_api(
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/pipeline.py", line 1259, in from_runner_api
part = context.transforms.get_by_id(transform_id)
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/runners/pipeline_context.py", line 115, in get_by_id
self._id_to_obj[id] = self._obj_type.from_runner_api(
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/pipeline.py", line 1259, in from_runner_api
part = context.transforms.get_by_id(transform_id)
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/runners/pipeline_context.py", line 115, in get_by_id
self._id_to_obj[id] = self._obj_type.from_runner_api(
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/pipeline.py", line 1236, in from_runner_api
transform = ptransform.PTransform.from_runner_api(proto, context)
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/transforms/ptransform.py", line 700, in from_runner_api
return constructor(
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/transforms/core.py", line 1419, in from_runner_api_parameter
DoFnInfo.from_runner_api(
File "/home/denes/data-science/venv/lib/python3.8/site-packages/apache_beam/transforms/core.py", line 1493, in from_runner_api
raise ValueError('Unexpected DoFn type: %s' % spec.urn)
ValueError: Unexpected DoFn type: beam:dofn:javasdk:0.1
{{}}
If I am not wrong, the problem is with the serialization methods. I have tried all sorts of combinations that I have found on [this|https://kafka.apache.org/26/javadoc/org/apache/kafka/common/serialization/] page.
When I do not specify the serializers then I get this error: {{RuntimeError:}}
{code:java}
Traceback (most recent call last):Traceback (most recent call last): File "/home/denes/data-science/try_write_to_kafka.py", line 48, in <module> run_pipeline(beam_options) File "/home/denes/data-science/try_write_to_kafka.py", line 14, in run_pipeline WriteToKafka( File "/home/denes/beam_kafka/venv/lib/python3.8/site-packages/apache_beam/pvalue.py", line 141, in __or__ return self.pipeline.apply(ptransform, self) File "/home/denes/beam_kafka/venv/lib/python3.8/site-packages/apache_beam/pipeline.py", line 689, in apply pvalueish_result = self.runner.apply(transform, pvalueish, self._options) File "/home/denes/beam_kafka/venv/lib/python3.8/site-packages/apache_beam/runners/runner.py", line 188, in apply return m(transform, input, options) File "/home/denes/beam_kafka/venv/lib/python3.8/site-packages/apache_beam/runners/runner.py", line 218, in apply_PTransform return transform.expand(input) File "/home/denes/beam_kafka/venv/lib/python3.8/site-packages/apache_beam/transforms/external.py", line 318, in expand raise RuntimeError(response.error)RuntimeError: java.lang.ClassCastException: class org.apache.beam.sdk.coders.VarLongCoder cannot be cast to class org.apache.beam.sdk.coders.KvCoder (org.apache.beam.sdk.coders.VarLongCoder and org.apache.beam.sdk.coders.KvCoder are in unnamed module of loader 'app') at org.apache.beam.sdk.io.kafka.KafkaIO$Write.expand(KafkaIO.java:2295) at org.apache.beam.sdk.io.kafka.KafkaIO$Write.expand(KafkaIO.java:2088) at org.apache.beam.sdk.Pipeline.applyInternal(Pipeline.java:547) at org.apache.beam.sdk.Pipeline.applyTransform(Pipeline.java:498) at org.apache.beam.sdk.expansion.service.ExpansionService$TransformProvider.apply(ExpansionService.java:360) at org.apache.beam.sdk.expansion.service.ExpansionService.expand(ExpansionService.java:436) at org.apache.beam.sdk.expansion.service.ExpansionService.expand(ExpansionService.java:491) at org.apache.beam.model.expansion.v1.ExpansionServiceGrpc$MethodHandlers.invoke(ExpansionServiceGrpc.java:232) at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.stub.ServerCalls$UnaryServerCallHandler$UnaryServerCallListener.onHalfClose(ServerCalls.java:172) at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.internal.ServerCallImpl$ServerStreamListenerImpl.halfClosed(ServerCallImpl.java:331) at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.internal.ServerImpl$JumpToApplicationThreadServerStreamListener$1HalfClosed.runInContext(ServerImpl.java:817) at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37) at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:834)
{code}
{{}}Note that I have installed the latest apache-beam version via {{pip install 'apache-beam'}}.
* apache-beam==2.28.0
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